experimental destroy_on_exit option for statically linked mimalloc in a dynamically unloaded DLL

include/mimalloc-internal.h

@@ -139,6 +139,7 @@ uint8_t    _mi_bin(size_t size);                // for stats
 void       _mi_heap_destroy_pages(mi_heap_t* heap);
 void       _mi_heap_collect_abandon(mi_heap_t* heap);
 void       _mi_heap_set_default_direct(mi_heap_t* heap);
+void       _mi_heap_destroy_all(void);
 
 // "stats.c"
 void       _mi_stats_done(mi_stats_t* stats);

include/mimalloc.h

@@ -335,6 +335,7 @@ typedef enum mi_option_e {
   mi_option_max_errors,
   mi_option_max_warnings,
   mi_option_max_segment_reclaim,
+  mi_option_destroy_on_exit,          
   _mi_option_last
 } mi_option_t;